MATH

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Solve the following system of equations for the unknown variables.
a + b = 7
a + c = 12
b + c = 15

  • MATH -

    a + b = 7
    a + c = 12
    ----------------subtract
    b - c = - 5
    then
    b - c = -5
    b + c = 15
    ----------- add
    2 b = 10
    b = 5
    you take it from there

  • MATH -

    A+B=7, A=7-B---(1)
    A+C=12,---(2), frm 1 substitute the value of A into eq 2 :7-B+C=12, C=12-7+B---(3)
    also B+C=15---(4), also in the same way put C in eq3 into eq 4 ;B+12-7+B=15, B=5, now rem eq1 put B into it ;A=7-5=2 do the same thin 4 C by putin B in eq3 C=5

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